Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

The last time I talked about this study was in the context of the carcinogens in the smell of frying bacon—the ability of the fumes generated by frying meat to mutate DNA, potentially explaining both the “increased risk of respiratory tract [cancer] among cooks” as well as the “lower proportion of deaths from respiratory diseases and lung cancer among vegetarians.”

This was borne out in a new study on the exposure of pregnant women to both the consumption of grilled meat, as well as just exposure to the airborne fumes of grilling meat—even if they didn’t eat it. Yes, the study found evidence that prenatal exposure to polycyclic aromatic hydrocarbons from a “diet including grilled meat might be hazardous for fetal development.” For example, the “effect of ingested barbecued meat consumed in the last pregnancy trimester resulted in [a] birth weight deficit of 165 g,” a significantly smaller birth weight.

But, even if she didn’t eat it, airborne exposure alone amounted to a birth weight deficit. Compared to no exposure, oral or airborne, just being around the barbecue was associated with a birth weight deficit, including a smaller head circumference in the newborn—nearly the same head shrinkage seen if she actually ate the meat. See, “[a]fter being absorbed into the body, [these cooked meat] compounds are distributed to almost all internal organs and are transferred through the placenta to the fetus,” and it appears “that newborns and young children are especially vulnerable to the toxic effects…in terms of birth outcomes. Most importantly, it was recently documented that prenatal exposure to airborne PAH may also have an effect on the future cognitive development of children.” We should never smoke around children; maybe, we should stop grilling around them, as well.

Even just living next door to a restaurant preparing meat may pose a hazard. They measured the “incremental lifetime cancer risk,” the excess cancer cases expected in back-door neighbors of restaurants, given what’s spewing out of the exhaust outlets attached to the fume hoods in the kitchen.

They compared what was coming out of Chinese restaurants, American-style restaurants, and barbecue joints. Which do you think was worse? It was the Chinese! Why not the barbecue places? Well, they think it was because of the fish. They’re broiling more fish in Chinese restaurants than in the barbecue joints.

How bad is it? Well, they estimate that given the excess cancer risk, you wouldn’t want to live behind a Chinese restaurant more than a day or two a month—though maybe you could squeeze in an extra day behind one of the other restaurants.

Their model suggests it may be riskier for adults, since they breathe more, eat more, and have more skin for the carcinogens to be absorbed through, compared to children. Instead of trying to breathe less, though, it might be better to just move—or, convince the restaurant to go vegetarian.

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

The last time I talked about this study was in the context of the carcinogens in the smell of frying bacon—the ability of the fumes generated by frying meat to mutate DNA, potentially explaining both the “increased risk of respiratory tract [cancer] among cooks” as well as the “lower proportion of deaths from respiratory diseases and lung cancer among vegetarians.”

This was borne out in a new study on the exposure of pregnant women to both the consumption of grilled meat, as well as just exposure to the airborne fumes of grilling meat—even if they didn’t eat it. Yes, the study found evidence that prenatal exposure to polycyclic aromatic hydrocarbons from a “diet including grilled meat might be hazardous for fetal development.” For example, the “effect of ingested barbecued meat consumed in the last pregnancy trimester resulted in [a] birth weight deficit of 165 g,” a significantly smaller birth weight.

But, even if she didn’t eat it, airborne exposure alone amounted to a birth weight deficit. Compared to no exposure, oral or airborne, just being around the barbecue was associated with a birth weight deficit, including a smaller head circumference in the newborn—nearly the same head shrinkage seen if she actually ate the meat. See, “[a]fter being absorbed into the body, [these cooked meat] compounds are distributed to almost all internal organs and are transferred through the placenta to the fetus,” and it appears “that newborns and young children are especially vulnerable to the toxic effects…in terms of birth outcomes. Most importantly, it was recently documented that prenatal exposure to airborne PAH may also have an effect on the future cognitive development of children.” We should never smoke around children; maybe, we should stop grilling around them, as well.

Even just living next door to a restaurant preparing meat may pose a hazard. They measured the “incremental lifetime cancer risk,” the excess cancer cases expected in back-door neighbors of restaurants, given what’s spewing out of the exhaust outlets attached to the fume hoods in the kitchen.

They compared what was coming out of Chinese restaurants, American-style restaurants, and barbecue joints. Which do you think was worse? It was the Chinese! Why not the barbecue places? Well, they think it was because of the fish. They’re broiling more fish in Chinese restaurants than in the barbecue joints.

How bad is it? Well, they estimate that given the excess cancer risk, you wouldn’t want to live behind a Chinese restaurant more than a day or two a month—though maybe you could squeeze in an extra day behind one of the other restaurants.

Their model suggests it may be riskier for adults, since they breathe more, eat more, and have more skin for the carcinogens to be absorbed through, compared to children. Instead of trying to breathe less, though, it might be better to just move—or, convince the restaurant to go vegetarian.

24 responses to “Meat Fumes: Dietary Secondhand Smoke”

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Many food stores intentionally exhaust cooking fumes from their deli department into their entrances. It has been shown to increase the amount of food purchased in that store. I try not inhale, just like Bill Clinton.

The absolute best restaurant in my town, bar none, is a vegan Chinese place. Absolutely delicious! I recommend looking around your town to see if you have something similar. I live in a relatively small city and we still have a restaurant like this. It is not advertised that way, so you have to look to find it. Maybe your city will have something similar – all the traditional Chinese foods you are used to, plus other dishes, and still all vegan. Perfect!

The Jedrychowski study seems like one that faces a huge correlation/causality hurdle. I suspect next to impossible to separate effects on fetal development from inhaling BBQ fumes and other environmental impacts of living in the same household environment.

The Chen study is much more compelling here. Continuous restaurant fumes and somewhat randomized back-door neighbors would tend to cancel out household to household environmental variation.

I was just sent this email: I’M NOT UP FOR GEWTTING INTO A DEBATE WITH YOU EVERY TIME I WRITE SOMETHING ON MY WALL ABOUT VEGANISM, THE EVIDENCE IS CONCLUSIVE FOR ME, VEGAN DIETS KILLED OR MAIN PEOPLE . SO EITHER STOP POSTING ON MY WALL OR I WILL REMOVE YOU. I DO NOT WISH TO PUT MY ENERGY IN THE DIRECTION OF SOMEONE WHO DISCOUNTS OTHER PEOPLES EXPERIENCES IN THE PURSUIT OF HIS OWN AGENDA !

The comment:

(January 31, 2013): What she says on the link is misleading. She equates a vegetarian diet as being bad for the planet because it involves cutting down the rainforests and destroying the planet’s topsoil. But all that deforestation is to grow grain for factory farms. Vegans don’t advocate for that. Grasses are good as they hold the topsoil, but why have pasture land for grass-fed, methane-farting cows? That’s still the animal-slaughter business. Plant fruits trees and walnut trees with gardens in between. Fruit sugar, carbs, is what the human brain runs on. There can be some animals, but they are for loving, not eating. Lierre Keith slanders the vegan lifestyle, yet apparently she was never really a vegan, and her logic in equating bad agriculture and a vegan lifestyle is flawed. The science, nutritionfacts.org, China Study, etc., demonstrate that it is the animal protein and fats, not only the pesticides and hormones of modern factory farming, that stimulates cancer and causes heart disease and so many illnesses.

What are the best studies to show this ? Has anyone looked at large populations over a long period ? I wonder whether the negative effects of eating meat might be largely cancelled out by only using lower temperature cooking methods ?

I have a nitrate sensitivity (acts like an allergy: hives, itchy throat, burning tongue). Recently, have had some mild reactions when around ball games, food courts, etc. I was wearing gloves and did not eat anything. Can nitrates be carried through the air?

Does just being in a room that smells like cigarette or next to a smoker( when they don’t smoke)
raise cancer risk too? Since you can still smell it, that means there is airborn contaminats in the
air is that right?

Excellent question! This is now called “Third Hand Smoke”. We have no evidence either way at this point but it is likely being researched as we speak. My guess is that you are correct and that this is hazardous, especially to babies that would be crawling on floor or wrapped in a blanket saturated with these residual toxins.